Coffee roasting machine



S. E. RICHESON COFFEE ROASTING MACHINE Aug. 1%, 1937.

4 Sheets-Sheet 1 Filed Aug. 1, 1956 SA NFORD E. R/CHESON I NVENTOR ATTORNEY g: 9, 1937. s. E. RICHESON 2,939,653

COFFEE ROASTING MACHINE Filegi Aug. 1, 1936 4 Sheets-Sheet 2 SANFORDER/CHESON INVENTOR y Quit w P. Mom ATTORNEY Aug. 10, 1937.. s. E. RICHESON COFFEE ROASTING MACHINE 4 Sheets-Sheet 4 Filed Aug. 1

SA NYFORD E. Rzch'sso/v v NV ENTOR 741w l7. Wmwb ATTO R N EY Patented Aug. 10, 1937 PATENT. OFFICE COFFEE ROASTING MACHINE Sanford E. Richeson, New York, N. Y., assignor to Richeson Company, Inc., New York, N. Y., a corporation of New York Application August 1, 1936, Serial No. 93,844

11 Claims.

My invention relates to coffee roasting machines and has particular reference to machines for roasting coffee beans by a continuous process.

The object of my invention is to provide a machine with a revolving roasting cylinder, into which a measured quantity of coffee beans is admitted at predetermined intervals of time, means being provided for moving the beans along the cylinder while they are being subjected to a roasting heat, and then periodically discharging roasted beans by definite portions, thereby maintaining an'automatic and continuous passage of the beans through the cylinder.

Another object of my invention is to provide means for electrically heating the air for roasting the coffee beans, the electric heater being provided with an automatic temperature control adapted to maintain the desired average temperature throughout the roasting chamber.

Another object of my invention is to provide means for automatically separating the roasted beans from the chafi, for which purpose the discharged beans from the roasting chamber are passed over a series of shaking screens.

Another object of my invention is to provide means for preheating the air before it is passed through the electric heater. For this purpose the fresh air is first passed through hollow bottoms of the shaking screens, where the air is heated by the hot beans, the latter being cooled thereby. A means is also provided for circulating the preheated air from the shaker bottoms through a heat exchanger for further heating the air by the exhaust fumes and smoky air from the roasting chamber; the partly preheated air being then finally preheated by passing it through a jacket around the roasting cylinder; and the finally preheated air is then admitted to the heating element at the end of the cylinder.

- An arrangement is also provided for exhausting the used hot air with smoke from the roasting chamber and usingit in the heat exchanger for preheating the fresh air. i

Still another object of my invention is to provide means for washing and purifying the exhaust smoky air from-the roasting chamber,- after its heat has been used for preheating the fresh air, for either discharging into the atmosphere or using it again in the machine.

5 My invention is more fully described in the accompanying specification and drawings in which- Fig. 1 is asectional elevation ofmy machine; Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fi 1;

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 1;

Fig. 5 is a fractional sectional view taken on 6 the line 5-5 of Fig. 2;

Fig. 6 is a detail view of the electric heater and temperature control device.

My coffee roasting machine consists of a housing I open on top and provided with a cover 2. l0

A hopper'3 is-supported in the upper portion of the housing for loading raw beans into the machine. Glass windows 4 are provided in the housing above the hopper for observing the beans in the hopper. The latter has a horizontal cylin- 1 drical' housing 5 in its lower portion for an automatic feeder. The latter consists of a hollow cylinder 6 mounted on a shaft 1 journaled in the sides of the housing 5. The shaft extends to the wall of the housing I where it is supported in 20 a bearing 8 and has a sprocket wheel 9 connected by a chain H] with a driving sprocket II on a shaft I2 journaled in a bearing H! at one end. The other end of the shaft I2 is journaled in brackets l4 and has aworm gear [5 in mesh with 25 a worm l6 on a short shaft l7 journaled in a bearing I8 and bracket IS, the latter being supported on a floor plate 20. The end of the shaft l1 outside of the bracket l9 carries a female part 2| of a magnetic cone clutch enclosed by 30 a stationary magnet coil 22. The male portion 41 of the clutchis slidably fitted on the end of a shaft 23 of a reduction gear box 24 operated by an electric motor 25. The cone 4! is keyed on the shaft 23. The latter has a pinion 30 in mesh with 3.3 an idler gear 3| rotating on a shaft 32 supported in brackets 33 suspended from an upper deck or floor plate 34. The gear 3| is in mesh with a ring gear 35 mounted on the rear end of a tubular casing 36 rotatively supported in a ball 40 bearing 31 mounted in a bracket 38 supported on the plate 34. The rear end of the casing abuts the lower end of a spout 39 extending from the feeder housing 5 and is provided with. a spiral rib 40, the direction of the spiral being such as 5 to cause the material delivered by the feeder into the casing to be moved forward bythe rotation of the casing 36. The spout with the feeder housing is supported on a standard 42 resting on the plate 34. A lug ll extends from the feeder housing and is attached to the bracket 38. The coil 22 is connected by leads 25 with a clock mechanism 29, the latter being in turn connected by leads 2'! witha source of electric power 28. The clock is adjusted so that it closes the current for the coil 22 at predetermined intervals of time, the current being closed for the length of time sufficient to permit the feeder cylinder 6 to make one complete revolution, ending with its position shown in Fig. l for discharging the material into the spout 39.

The bearing 31 is closed at the front side by a wall 43forming an annular chamber 44 with a wall 45 of the casing 36, this wall 45 connecting the rear portion of the casing with its enlarged front portion. The wall 45 has holes 46 extending into the chamber 44. A tapering cylinder 48 is attached by its rear end to the front end of the casing 36, a flange 49 on the cylinder being held by a ring-shaped clamp 50. The front end of the cylinder has a flange 5| with holes for bolts 52 which fasten a rounded cap 53 to the cylinder, the cap having a corresponding flange 54 with holes for the bolts 52. A bafiie plate 55 is clamped between the cylinder and cap. The cap has an opening 56 in the front portion, and the plate 55 has an opening 51 in the central part. The cylinder 48 has a spiral rib 58 inside arranged'in the same direction as the rib in the casing. The rib 58 is formed by depressing the material of the cylinder on the outside so as to maintain the uniform thickness of its walls. The cylinder, the cap 53 and the baffle plate 55 are made of a transparent heat resisting material, preferably quartz or glass of a high silica content. The space inside of the cylinder represents a roasting chamber 59.

The cylinder 48 is enclosed outside by an outer cylinder 60' also made of a transparent material, but not necessarily'of a highly refractory type, and ordinary glass may be used, as this cylinder is not subjected to a very high temperature. It

- the casing 36.

65 opening into the space 6|.

5 the end portion forms an-annular chamber 6| with the inner cylinder 48. It has a flange 62 at the rear end, held bya'ring-shaped clamp 63 against a radial wall 64 on the casing 36. The wall 64 has apertures The enlarged portion of blower 66 enclosed by a housing 61 supported on the inside of the housing I oi the machine. The blower has an intake opening 61 in communication with an air chamber 68 to which air is conducted by a pipe 69. A shield 10 extends from the casing 36 forming support for the clamp 62 and directing air from the blower through openings 1| into the space 6|.

A discharge port 12 is provided at the rear end of the roasting chamber 59 and is closed by a cover 13. The latter is connected with a bell crank 14 the other end of which is connected with a rod-15 slidably fitted in, the trunnion portion of The rod 15 is connected by a bolt 16 passing through a slot 11 with a sliding collar 19 which can be moved between the gear 35 and a.

bearing retaining nut 80. The collar 19 is en-' gaged by pins 8| on the ends of a fork 82 pivotally supported at 83 on the housing 5. The other end of the fork has a cam 84 which is engaged by an eccentric pin 85 with a'roller secured-on of the feeder cylinder 6. The pin 85 is located so that it engages the cam 84 when the feeder cylinder is turned upwardly with its port 86 for receiving the fresh charge of a material from the hopper 3, at which timethe fork operates the crank lever and opens the door or cover 13.

Heat for the roasting chamber is provided by an electric heater 81, which 'may represent a spirally wound coil. 88 of a heat resistant wire,

such-as nichrome, on a cylinder 89 made of an i an asbestos composition, porcelain, etc.

the casing 36% has a horizontal shaking movement.

thereby formed is closed by a flexible tubing I28 insulating and heat resistant material, such as The cylinder is mounted on the end of a tubular member 90 passing through the opening 51 in the plate 55.

The rod 90 forms an extension of a tubular rod 9| to which it is attached by an insulated coupling. The latter consists of a heat insulating disc 92 clamped between flanges 93 and 94 on the ends of the rods 90 and 9| by bolts 95. A metal disc 96 is held on the flange 93 by the bolts 95. This disc, which may be made of metal, is less than the inside diameter of the cylinder 48, leaving an annular clearance 91, sufiiciently narrow to prevent the escape of the roasted material. It has also small holes 98 for air circulation.

The other end of the tubular rod 9| is screwed into the supporting member 42. connected by leads 99 and I00 with the supply circuit 28.

The heater is controlled by a thermostatic element consisting of a tube |0I slidably fitted on the rod 9| and fastened to it at one end by a screw I02. The other end of the tube passes through a corresponding hole in the wall of the spout 39 and has a collar I03 which is clamped on the tube by a bolt I04. The collar has a clevis I05 engaging a pin I06 on the end of an arm I01 of an electric switch I08. The pin is made.

smaller than the holes for it in the clevis to allow for a free movement of the arm. The latter'is pivotally connected at I09 to a lug H0 and has a short-circuiting contact member III clamped on an insulation sleeve H2. The member III establishes a contact between points H3 and 4 connected by leads II5 with the leads 99 and I00 through a shortcircuiting resistance H6. The tube IIII is made of a metal having high tempere ature coefficient, preferably of a copper alloy, while the rod 9| is made of a metal having low temperature coeflicient, preferably a ferric alloy, for instance, invar. the outer end, can freely expand, moving its other end along the central rod. It is possible, of course, to reverse the arrangement of thermostatic metals, making the tube of invar and the rod of brass. The switch then must be reversed for the same operation of the electric circuits.

An additional contact point H1 is provided in the switch for closing the circuit for the coil 22 I directly by, the thermostatic element, as shown in Fig. 6, through leads 8 and 9. This arrangement is required when the roasting operation is carried only until the desired temperature is reached. The lead II9 may be disconnected pended from the screen I22 on braces I25 and is inclined toward the rear where it has a discharge spout I26, extending into a discharge port I21. The port I21 is longer inside than the spout I26 so as to admit a certain degree of freedom for The clearance made preferably of rubber or similar elastic mate-- rial. The rear end of the lower screen is con- 'nected by a bar I29 with an eccentric pin I30 on a vertical shaft I3I journaled in bearings I32 and I33 mounted on the underside of the The heater is The tube, being held fast at 25 I52 forming a heat exchanger.

plate 34. The shaft I3I has a bevel gear I34 in mesh with a gear I35 on the extension of the transmission shaft 23. The bar I29 is pivoted at both ends and converts the rotary movement of the shaft I3I into longitudinal oscillations for the ,shak er s c reens. The screens are built as hollow fiat 'bpp e with intermediate partitions I36 and I31, forinig flcma i mbers I38, I39, I40 and The lower chambers i l, and I4I are connected with the shaker plates on top by ducts I42 for the chaff and other foreign particles which may be present in the roasted material. These chambers are connected by pipes I43 with a preheatmg chamber I44, the pipes I43 being also connected with a pipe I45 extending from the annular chamber 44.

The upper chambers I38 and I39 are connected by flexible pipes I46 and I41 with an intake port I48 closed by a screen I49. Similar flexible pipes I50 and I5I connect the rear endsof the 1 chambers I38 and I39 with a heating coil -I52 placed in the preheating chamber I44,the chamher or compartment I44 together with the coil The coil I52 is connected by a pipe 69 with the intake chamber 68 of the blower 66, and the chamber I44 is connected by-a pipe I53 with the intake of a blower I54 directly connected with the motor 25. A pipe I55 extends from the intake of this blower to the space in the housing I. The exhaust of the blower I54 is connected by a pipe I56 with an air washing chamber I51 in the base of the machine under a floor plate I58 and separated from a cleaning chamber I60 by a low wall I59. The washing chamber is partly filled with a suitable liquid; preferably water solution of chemicals which can dissolve or absorb impurities present in the air from the roasting chamber. Baiile plates or screens I6I are suspended from the plate I58 and are partly immersed in the solution I62. The cleaning chamber "50- contains staggered plates I65, partly suspended from the plate I50, partly mounted on the plate I63. A pipe I64 extends from the cleaning chamber I60 to a box I13 under the hopper 3, the box being connected with the space in the hopper by small holes I14. In the spaces between the bailie plates I65 an absorbent material I66 is placed..such as an activated carbon. A door I61 is provided for the removal of the finished product, as may be observed through a window I68. A door I69 is used for the replacement of carbon I66, and plugs I10 and "I are provided for the removal and replacement of the solution I62.

The operation of my machine is as follows. The raw material, such as coffee beans, corn. small nuts, or similar products, is placed in the hopper 3. The motor.25 is started, and the ourrent for the heater 88 is turned on by a switch I15. The time switch 29,- being set for a certain length 'of time required for roasting the material, closes the circuit for the coil 22 after such time intervals, thereby engaging the clutch members 2I and 41. The worm I6 will accordingly rotate turning the gear I5 and shaft I2, which transmits the rotation through the chain I0 and sprocket 9 to the shaft 1 and the feeder drum 6. The latter, upon making one half revolution. will face the hopper 3 with its port 86 and will become fllled by the material. 'With the further rotation of the feeder, it will be cut of! from the feeder,

, the port 86 facing the wall 5 until, upon completion ofthe revolution, it returns to its original position'shown in Fig. 1,'with the port 96 opening into the spout 39, allowing the material to flow through the spout into casing 36. The material will continue to move forward, being propelled by the spiral rib 40, until it falls into the larger front portion of the casing. Here it will be moved further by the rib 58, the overflow falling back again, the whole volume or bulk of the material being thereby thoroughly stirred thereby obtaining a uniform heating throughout.

The time switch or clock 29 is set so that it keeps the circuit for the coil 22 closed for the length of time required for one revolution of the feeder drum 6, the feeder remaining stationary during the subsequent period when the material is being roasted. The drum 6, upon completion of about one half revolution and when in the receiving position, engages by the roller the cam 84, thereby shifting the fork 82. The latter pulls on the rod 16 and turns the crank 14, opening the cover 13 and permitting the roasted material to drop'through the chute I2I on the upper shaker screen, from which it flows on the lower screen I24 and, finally, drops through the discharge port I26 on the floor I58 in the delivering chamber I12. With the location of the roller. 85 as shown, the charging of the roasting cylinder with the fresh material and the discharge of the roasted material do not occur simultaneously, the latter operation taking place before the new charge is admitted. This arrangement eliminates the possibility of any portion of the fresh material from being discharged with the roasted product.

The shakers I22 and I24 are continuously reciprocated by the eccentric pin I30 and link I29 from the shaft' I3I. The material is thereby energetically stirred and freed from chaff and dust, which fall through the ducts I42 into the lower collecting chambers I40 and MI. The removal of chafi is facilitated and expedited by the air suction created by the blower I54 and transmitted through the pipes I43, heating chamber I44, and pipe I53. The blower I54 also sucks the smoky air from the upper part of the housing I, where it accumulates as a result of leakage from various joints, particularly between the spout and the rear end of the trunnion portion of the casing 36, the pipe I55 serving for the .purpose of removing this smoky air.

The smoky exhaust air from the blower is delivered by the pipe I 56 into the washing well I51 where it passes through the liquid I62 between screen baflles I6I. The liquid, which may be pure water or water solution of suitable chemicals. removes a large portion of mechanically entrained dust and smoke particles, also certain soluble vapors. The air is finally purified by removing gases and the balance of vapors in the chamber I60 by the activated carbon I66 or similar absorbing (or adsorbing) agent. The purified air, which is still warm, is delivered by the pipe I64 to the raw material in the hopper 3 for its preheating.

Air for the heater'is drawn by the blower blades 66 on the casing 36, which is continuously rotated by the motor 25 through the train of gears 30, 3I and 35. The air enters through the screen I49 and passes through the chambers I 38 and I30, being heated by the hot material freshly delivered from the roasting chamber 59. The air I is then further preheated in the coils I52 surrounded by the hot exhaust air from the pipe I43. It then passes through the pipe 69 to the receiving chamber ,66 to be drawn by'the blades 66, forcing it into the annular space 6| where it becomes still further preheated by the contact with the hot wall of the roasting cylinder 48. Finally 'it enters the space under the cap 53 through the opening 56 and becomes heated to the roasting tempera- 5 ture by the electric heater 88. Itthen passes into the roasting chamber through the opening 51 and the annular clearance 91. The hot air passes over the material in the roasting chamber and is exhausted through the holes 46 into the chamber 44, from which it is drawn into the chamber I 'through the pipe I45.

The temperature in the roasting chamber and, more particularly, of the material being roasted, is maintained substantially constant by the thermostatic control apparatus connected with the heater 88. The thermostatic tube I I, being constantly surrounded by the material in the chamber 59, acquires its temperature and correspondingly expands, moving the handle arm I01 of the switch, unt l at the predetermined roasting temperature the switch closes the contacts between the points H5 thereby short circuiting or shunting the resistance 88 on the resistor H6. As a result, the current through the heater will be reduced, with the correspondingly lowered heat output. When temperature drops below the roasting limit, the tube l0! contracts, pullingthe arm I01 and opening the switch, thereby sending full current through the heater. The roasting operation thus continues until the timing switch 29 closes the circuit for the coil 22, causing the new charge to be delivered into the roasting cylinder,removing the roasted material.

In the arrangement shown in Fig. 6, the switch the circuit for the coil '22 by the action of the thermostatic element IOI. This operation. may be used when it is desired to stop the roasting operation as soon as the material reaches the 40 roasting temperature. The switch I20 is used for setting the machine in operation according to this plan. Additional parts of the clock mecha-' of the chamber, so that even" if these tempera- 'tures may difier somewhat, the combined effect will be equivalent to the average or mean temperature of the material, although, of course, the material, because of its constant stirring and moving, will rapidy attain a fairly uniform temperature throughout. The tube i0! is afiected only by the temperature of the material as the g0 latter flows over the tube, the material either heating or cooling the tube according to its own temperature. The tube is not affected directly by the temperature of the heater, being insulated therefrom by the spacer 92 and air baiiles 55 5 and 9a.

It may be also noted that while the feeder and the-discharge mechanism operate at the same time periods, they. differ in phase, so that the discharge port is never open at the same time as 70 the feederdelivers a fresh charge".

' With my system of air circulation a very big efliciency of heat utilization is obtained, the fresh air being preheatedby the exhaust air, while the latter is also washed and purified be- 75 fore its discharge into the 'atmospherathereby N18 has the third contact point I I! for closing preventing the escape of any unpleasant odors, smoke,.etc., and the purified air is finally used for preheating the raw material, thereby utilizing the remainder of its heat.

I claim as my invention:

1. A coffee roasting machine comprising a cylindrical container having a partly closed compartment at the end, means to rotatively support the container at the other end,'means. to rotate the container by its supported end, means to periodically charge the container with a raw material, means to discharge the product from the container, an electric heater in the compartment. an outer cylinder enclosing the container, means on the-container for blowing air through the cylinder and through the compartment into thecontainer thereby heating the material therein, and means to exhaust the used air from the container.

2. A coffee roasting machine comprising 2. cylindrical container, means to rotatively support the container, means to rotate the container, a hopper for a raw material, means to charge the container with the raw material from the hopper and to discharge the roasted product, an electric heater in the container, means on the container for delivering air into the container over the heater for heating the material therein, means to exhaust the used air from the container, means to .preheat the fresh air for the container by the exhaust air, means to wash the exhaust air, means to filter and purify the washed exhaust air and means to deliver the purified air to the hopper for preheating the raw material.

3. A coffee roasting machine comprising a cylindrical container, means to rotatively support the container, means to rotate the container, means to charge the container with a raw material an'd to discharge the roasted product, an electric heater in the container, means to deliver air into the container over the'heater thereby heating the material therein, shaker screens adapted to receive the product from thecontainer and having double compartments underneath, means to circulate air for the container through the upper compartments thereby preheating the airby the product, the lower compartments being connected with the screens by ducts adapted to receive the chaif from the product, means to exhaust the air with the chafl from the lower compartments, means to usethe air with the chaff for the further preheating of the air from the first compartment, means to exhaust the'used air from the container and to use it together with the air from the ,iower screen compartments for preheating the fresh air for the container, and means to wash and purify the exhaust air.

4. A coffee roasting machine comprising a container, a hopper for a raw material, means to charge the container with a raw material from the hopper and to discharge the product therefrom, means to deliver air into the container, means to heat the air to the predetermined temperature, means to exhaust the used air from the container, shaker screens for the product, means to oscillate the screens, means to preheat the air for the container by the material on the screens, a heat exchanger adapted further to preheat the air for the container by the exhaust air, means to wash the exhaust air, means to purify the washed air,

the hopper and to discharge the product thereaoeacos from, means to deliver air into the container, means to heat the air in the container to a predetermined temperature, means to exhaust the used air from the container, means to remove the chaff from the product by the blast of air, means to use the air with the chaff and the exhaust air for preheating the air for the container, a well adapted to contain a liquid for washing the exhaust air and the chafi, a plurality of baflie plates partly immersed in the liquid, a substantially flat container adapted to hold an air purifying substance, a plurality of staggered baflie plates in the flat container, the exhaust air being adapted to circulate through the well and the flat container, 15 and means to deliver the purified air to the raw material in the hopper for preheating the same.

6. A coffee roasting machine comprising a tubular container rotatively supported at one end, means to rotate the container by its supported 20 end, the free end of the container having a rela tively small aperture, an outer cylinder fully en.- elosing the free portion of the container, and spaced therefrom thereby forming an annular chamber, a rod extendingthrough the container 25 to its apertured end, an electric heater on the end of the rod near the aperture, means to deliver a raw material into the container, means to remove the roasted product therefrom, means to protect the heater from the material, and means 30 to blow air through the annular chamber toward the apertured end of the container and back through the container, the heater being adapted to heat the air for the container to the roasting temperature. '7. A cofiee roasting machine comprising a tubular container, means to rotatively support the container at one end, means to rotate the container. a housing enclosing the supported end of the'container, means to deliver a raw ma- 40 terial into the container, an outer cylinder extending around the container and spaced therefrom thereby forming an annular chamber around the container, the cylinder being closed around the free end of the container, the con- 5 tainer having a relatively small aperture in its free end, an enclosure in the housing around the supported end -of the cylinder, means to blow air through the enclosure into the annular chamber and therefrom through the aperture and through the container, means to heat the air for roasting the material, means to remove the roasted product from the container, means to admit the exhaust air from the container into the housing. means to remove and to purify the 55 air from the housing, and means to deliver the purified air to the blowing means.

8. A coffee roasting machine comprising a tubular container, means to rotatively support the container, means to rotate the container, a

60 hopper for a raw material, a feeder for the raw material movably supported between the hopper and the container, an operative connection between the feeder and the container rotating means, a magnet controlling the operative connections, means to roast the material in the container, means to discharge the roasted product from the container, means to control theydischarging means by the feeder, and means to render the feeder operative at predetermined periods of time.

9. A coffee roasting machine comprising a tubular container, means to rotatively support the container, means to rotate the container, a hopper for a raw material, a feeder movabhz supported between the hopper and the container, means to operate the feeder, a clock mechanism adapted to render the feeder operating means operative at predetermined periods of time, means to limit the movement of the feeder to one cycle of operations, electrical means to roast the material in the container, a thermostatic 'means to control the'roasting means, and

' means operated by the feeder for discharging the roasted material from the container.

10. A cofl'ee roasting machine comprising a tubular container, means to rotatively support the container, means to rotate the container, a hopper for a raw material, a feeder rotatively supported between the hopper and the container, means to rotate the feeder, a clock mechanism adapted to render the feeder rotating means operative at predetermined periods of time, means to roast the material in the container, feeder operated means for discharging the roasted product from the container; and means to control the roasting temperature, the clock mechanism being terial to move over the shakers, the shakers being provided with a plurality of small apertures for extracting chaff fromthe material, enclosures for the shakers, means to admit fresh air into the enclosure, means to exhaust the air, heated by the material, from the enclosures, means to deliver the heated air to the container, and flexible connections for the air between the shakers and stationary. portions of the air admitting and exhausting means.

mm) E. RICHEBON. 

